s = "Hello,Python world!"
print(len(s))
print(s.count("o"))
print(s.upper())
print(s.lower())
s.replace("world", "universe")
print(s.startswith("Hello"))
print(s.endswith("!"))
print(s.split(","))
print(s.strip("!"))
for i in s:
    s1 = s[::-1]
print(s1)
print(s[6:12])
print(s[0:6] + s[-6:])
print(s.replace("Hello,", ""))
print(f"{s}{2021}")
print(s.find("a"))
print(s.rfind("e"))
print(s.count(" "))
for i in s:
    print(i)
li = []
for i in s:
    li.append(i)
print(li)
li1 = list(s)
li1.sort()
s2 = str(li1)
print(s2)
print(s.isdecimal())
l = ['Hello,', 'Python', 'World!']
s3 = " ".join(l)
print(s3)
print("%s: 100" % s)
print(s.islower())
print(s.isupper())
l1 = [1,2,3]
# st_l1 = list(map(str,l1))
st_l1 = ""
for i in l1:
    st_l1 += str(i)
s4 = "-".join(st_l1)
print(s4)
pos = []
for i, c in enumerate(s):
    if c == "o":
        pos.append(i)
print(pos)

for i, c in enumerate(s):
    if c == "o":
        break
print(i)

s5 = s[:6]+"amazing"+s[6:]
print(s5)